Dial instrument



Dec.V 23, 1941. J. v. TRACY DIAL INsTRuMENT Filed July 17,- 1940 Patented Dec. 23, 1941 UNITED STATES TENT QFFICE DIAL INSTRUMENT Joseph V. Tracy, Fairfield, Conn., assigner to Manning, Maxwell & Moore, Incorporated, New York, N. Y., a corporation of New Jersey Application July 17, 1940, Serial No. 345,923

. l Claims. V4(Cl. i3-109) This invention pertains to instruments, for example pressure gauges or dial thermometers,

4wherein an index or pointer moves over a graduated dial in response to variations in some physical quantity which are to be indicated or recorded.

Among the objects of the invention are to provide an instrument of simple, durable and inexpensive construction and comprising a minimum number of parts; and in particul-ar to provide novel means for uniting the dial and movement frame to the socket shank of the instrument and for attaching the latter to the instrument case.

Other objects and advantages of the invention lwill be pointed out in the following more detailed description and by reference to the accompanying drawing wherein- Fig. 1 is a front elevation of one desirable embodiment of the invention;

Fig. 2 is a side elevation of the instrument of Fig. 1 with certain parts broken away and in vertical section;

Fig. 3 is a fragmentary front elevation of the instrument of Fig- 1, indicating some of the thiscase comprises the side wall I and the rear l Wall 2, the side wall being -provided with an aperture for the entrance of the upper portion of the socket shank 3, such socket shank, as here illustrated, being substantially square in horizontal section and having at its lower end the integral screw-threaded nipple 4. VWhile, as here illustrated, the socket shank 3 enters through an opening inthe side wall I of the casing, it is contemplated that in accordance with Ycommon practice this socket shank may be arranged to enter an opening in the rear wall 2 of the casing if preferred. The rear wall 2 of the casing is preferably provided with a depressed area 2c!r (Fig. 4) providing aV space for the reception of the heads 5 of a pair of screws whose threaded Shanks extend through apertures in the depressedvportion 2a of the rear wall 'and into the screwthreaded rear ends of bores 6 formed in the socket shank 3. These bores extend entirely through the socket shank 3, but as illustrated in Figs. 4 55 and 5 Yare of smaller diameter at their forward ends than at their rear ends.

The front of the case is normally covered by a removable cap or cover comprising the transparent panel portion I (Fig. 2) andthe peripheral ange 8, the'latter being designed to t snugly over the sidewall of the case and to be retained in place 'by friction. Preferably this cap is of unitary constructionv consisting of a moulded transparent material, for Vinstance one of the synthetic' resins, and'since all of this cap may thus be transparent, the entire area of the front of the 'casing may be exposed to view through the cap, it being noted, as shown in Fig. 1, that even the thin forward edge Ix of the wall I of the casing is thus exposed to view. Preferably the cap is provided with a reinforced or thickened portion 9, such thickened portion being arranged to overlap the forward surface 3a, of the socket shank 3 and preferably being provided with a recess I or being slightly vspaced from the face 3a of the socket shank, so as to permit the insertion of a suitable tool such as a screw driver for prying'the cap olf from the front of the case. While a cap of somewhat resilient material having a snap fit over the front of the case is preferred, it is to be understood that the invention is not necessarily rlimited to such an arrangement but that other modes of attaching the cap to the case may be employed if desired. The dial II is preferably disposed'very close to the plane of the front edge la: of the case and since, as above noted, the entire cap is transparent, the marginal portion of the dial is thus fully exposed to view. Thus the designating characters (indicated by the numeral I2) may be arranged very close to the edge of the dial and the graduations (indicated at I3) may be disposed inwardly of these designating characters so that the central portion I4 of the dial (bounded by the arc dened by the inner ends of the graduations) is thus left free and may be used, if desired, for the reception of trade names or the like. The dial is provided at its center with an opening through which the index staff I 5 projects, the index staff carrying the pointerV I6 which may, if desired, be provided with a short and heavy counterbalance arm Iial (Fig. 3).

Y Projecting forwardly from the dial'are stop pins II and I8, designed to limit the arc of movement of the pointer I6 in both directions. The

-index staff is actuated, through movement mechanism of any desired character, by the Bourdon tube B or its equivalent, 'the' movement'mechanism being carried by a rigid frame which comprises the downwardly extending supporting member I9 (Figs. 3 and 4). The lower part of this supporting member engages the front face 3a of the socket shank 3, being disposed between the face 3a and the dial ll. The stop pins I1 and I8 (Fig. 4) are provided with flanges or radial enlargements Ila and ISa respectively, which overlie the front face of the dial. These pins are also furnished with shank portions 20 and 2l, respectively, which extend through registering openings in the dial and the frame member I9 and into the forward small diameter portions of the bores 6 in the socket shank 3. The shank portions 2U and 2l may be smooth and designed to have a simple drive fit in the forward ends of bores 6; the shank portions 20 and 2| may be provided with a drive screw thread so that when driven or pressed into the forward ends of bores they will become firmly fixed in the unthreaded bores; or the shank portions may be threaded with ordinary machine threads (as i1- lustrated) the forward ends of hores 6 being correspondigly threaded. In the latter case the stop pins I1 and i8 are inserted by rotating them by means of a suitable tool engageable with the peripheries of the fianges lla and 18a (which may be polygonal to facilitate such operation) until the flanges lla, and 18a bear hard against the front face of the dial, thus clamping the dial and frame between the socket and said flanges and thereby firmly uniting the dial and the movement frame to the socket shank. The stop pins thus perform the several functions of limiting the movement of the pointer and of retaining the dial in position and securing the movement frame and the dial to the socket shank. By this arrangement the number of parts is reduced and a simplified and cheaper construction than usual is made available.

In the arrangement shown in Fig. the Shanks of the stop pins are not screw threaded into the forward ends of the bores B, but are headed .over at 22 against the shoulder provided where the forward and rear parts of the bore B join, thus furnishing a permanent connection between the dial, the movement frame and the socket shank.

It should be noted that in the arrangements illustrated the cap is of concave-convex form so that there is a substantial space forwardly of the dial in which the pointer may travel. With this arrangement it is possible to place the dial substantially in the plane of the forward edge Ix of the casing, as above described, so that no part of the dial is concealed by the edge of the casing. Thus the entire margin of the dial is exposed to view and may be clearly seen even when viewed from an angle.

While a desirable embodiment of the inventiongtogether with a certain modification thereof, has been illustrated and described by way of example, it is to be understood that the invention is not necessarily limited to the precise construction herein illustrated, but is to be regarded as broadly inclusive of any and all equivalents which fall within the terms of the appended claims. v

I claim:

1. An instrument cf` the class described having a movement frame, a dial, a pointer, means for actuating the pointer, a socket constituting a support for the movement frame, and a stop' pin'operative' to limit movement of the pointer in one direction, said pin having a shank portion which extends through aligned apertures in the dial and a part of the movement frame and into the socket, the pin also comprising a flange portion which engages the front face of the dial, the dial and frame being clamped between the socket and the flange of the pin thereby firmly uniting them to the socket.

2. An instrument of the class described having a movement frame, a dial, a pointer, means for actuating the pointer, a socket constituting a support for the movement frame, a stop pin operative to limit movement of the pointer in one direction, said pin having a shank portion which extends through aligned openings in the dial and a part of the movement frame, said shank portion of the pin being screw threaded and having threaded engagement with a threaded bore in the socket, the pin also comprising a flange portion which engages the front face of the dial, the dial and frame being clamped between the socket and the flange of the pin and being thereby firmly united to the socket.

3. An instrument of the class described having a movement frame, a dial, a pointer, means for actuating the pointer, a socket constituting a support for the movement frame, and a stop pin operative to limit movement of the pointer in one direction, said stop pin having a radial flange which engages the front face of the dial and a shank portion which extends through registering openings in the dial and a part of the frame and into the socket, said stop pin having screwthreaded engagement with the socket.

4. An instrument of the class described having a movement frame, a dial, a pointer, means for actuating the pointer, a socket constituting a support for the movement frame, and stop pins for limiting the path of movement of the pointer, said stop pins extending through the dial and a portion of the frame and into the socket, each pin also comprising a flange portion which engages the front face of the dial, the dial and frame being clamped between the socket and the flanges of the several pins, the pins constituting the sole means for uniting the frame and socket.

5. An instrument of the class described having a movement frame, a dial, a pointer, means for actuating the pointer, a socket constituting a support for the movement frame, said socket having a bore extending therethrough from front to rear, the bore being screw threaded, a stop pin operative to limit movement of the pointer in one direction, said pin having a shank extending through aligned openings in the dial and a part of the movement frame and into the forward end of the bore in the socket and having screwthreaded engagement with the threads of said bore, the pin also comprising a flange portion which engages the front face of the dial, the dial and frame being clamped between the socket and the fiange of the pin whereby the frame and dial are firmly united to the socket, a case which houses the dial and movement frame, and a screw which passes through an aperture in the case and which has screw-threaded engagement with the rear end of the bore in the socket.

6. An instrument of the class described having a movement frame, a dial, a pointer, means for actuating the pointer, a socket constituting a support for the movement frame, the socket having a bore extending therethrough from front to rear, the rear portion of the bore being screw threaded, a stop pin operative to limit movement of the pointer in one direction, said pin having a shank extending through aligned openings in the dial and a part of the movement frame and into the forward end of the bore in the socket, said shank being permanently secured Within said bore, the pin also comprising a flange portion which bears against the front face of the dial, the dial and frame being clamped between the socket and the flange of the pin and being thereby firmly secured to the socket, a case which houses the dial and movement frame, and an attaching member extending through an aperture in the case and into the rear end of the bore in the socket.

7. An instrument of the class described comprising a case having a rear Wall, a socket member extending through the case, a movement frame Within the casing, a pointer, a dial and a pin which unites the dial and movement frame to the socket, said pin also comprising a ange portion which engages the front face of the dial, the dial and frame being clamped between the socket and the flange of the pin and thereby rmly united to the socket, the pin also having a part which projects forwardly of the flange portion and which constitutes a limiting stop for the pointer.

JOSEPH V. TRACY. 

